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Automated commissioning of HVAC systems using first principle modelsKelso, Richard M. January 2003 (has links)
Commissioning of HVAC systems has potential for significant improvements in occupant satisfaction, comfort and energy consumption, but is very labour-intensive and expensive as practiced at this time. Previous investigators have capitalized on digital control systems' capability of logging and storing data and of interfacing with external computers for open loop control by developing methods of automated fault detection and diagnosis during normal operation. Some investigators have also considered the application of this technique in commissioning. This thesis investigates the possibility of utilizing first principles and empirical models of air-handling unit components to represent correct operation of the unit during commissioning. The models have parameters whose values can be determined from engineering design intent information contained in the construction drawings and other data available at commissioning time. Quasi-dynamic models are developed and tested. The models are tested against design intent information and also against data from a real system operating without known faults. The results show the models agree well with the measured data except for some false positive indications, particularly in the damper and fan models, during transients. A procedure for estimating uncertainty in the instrumentation and the models is developed. The models are also tested against artificial faults and are able to detect all of the faults. Methods of diagnosing the faults are discussed.
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Energieffektivisering av Lokverkstaden i Gamla Motala Verkstad : Uppvärmnings- och VentilationssystemNiyonkuru, Prosper, Mugisho, Marc January 2016 (has links)
Nästan alla forskningar om klimatförändringar påpekar att de accelererande klimatförändringarna vi ser till stor del orsakas av mänskliga verksamheter. Om vi inte reducerar energianvändningen kommer våra utsläpp av växthusgaser öka kraftigt och det kan leda till en katastrof i framtiden. För att vi ska klara morgondagen måste vi omedelbart börja begränsa vår energiförbrukning. I Sverige har regeringen som mål att minska energiförbrukningen med cirka 20 % från 1995 till 2020 och 50 % till 2050. Nästan 40 % av all energianvändning förekommer i byggnads- och fastighetssektorn. För att minska energianvändningen i den sektorn måste vi energieffektivisera även våra befintliga byggnader. En stor del av energianvändningen går till att täcka transmissionsförluster genom väggar, fönster och köldbryggor. Genom att välja fönster med låg värmeöverföring och rätt isolering till byggnader samt minska transmissionsförlusterna i ventilation och uppvärmning skulle mycket energi kunna sparas. Har en byggnad låg transmissionsförlust reduceras energibehovet markant. Genom att installera ventilationssystem med en värmeåtervinning (FTX) kan energiförbrukningen avseende förvärmd ventilation minskas kraftigt. Ventilation med värmeåtervinning gör det möjligt att återvinna energi från den utgående luften från lokalerna till den kalla uteluften som ska till lokalerna för att uppehålla en god inomhusmiljö, värmeväxlare har verkningsgrad upp till 0,85. För att energiförbättra gamla byggnader till energieffektiva, krävs nya installationer och ombyggnader för att anpassa till miljövänliga byggnader. Det kan ibland vara svårt att installera FTX-system i befintliga byggnader eftersom luftbehandlingsaggregat kräver stor plats. Den ekonomiska avskrivningstiden är lång. I det här examenarbetet kommer ventilations- och uppvärmningssystem att utredas; fokus ligger på installationsteknik samt energieffektivisering beroende på hur lokalen ska användas. Målet är att undersöka hur stort energibehov en byggnad har samt ge förslag till vilket ventilationssystem som passar byggnaden. Med hjälp av ritningar över Lokverkstaden och diverse information om lokalen skapades en modell i simuleringsprogrammet IDA ICE, en av de bästa simuleringsprogramvaror för energibehov i byggnader. När man hade fått fram en modell att jobba med började inmatningar och utfördes förändringar på byggnaden som motsvarar (med hjälp av) det indata man hade fått från beställaren. Ventilationsritningar utfördes i Magi Cad och en luftbehandling har dimensionerats på Swegons hemsida. Temperaturen i lokalen påverkas av olika faktorer såsom dålig isolering m.m. Lokalerna står i dag helt kalla men lokal uppvärmning förekommer vid extrem kyla för att hålla en del VVS så varmt att det inte fryser. Lokalerna har en stor fuktbelastning och en del av golvet består av en mycket tjock betongplatta. Resultatet visar att det bästa ventilationsaggregat som behövs för att klara av luftflödet på 11,6 m3/s, bör ha specifika fläkteffekten på 2,39 kW/(m3/s). Byggnadens energiförbrukning blev 610624 kWh om året i simuleringen. / Almost all research about climate change points to that the accelerating climate changes we see today, is to a large part caused by human activity. If we don’t reduce our energy usage, our emissions of greenhouse gases will increase heavily - which can lead to disasters in the future. To be able to solve potential problems and avoid disasters in the future, we have to start decreasing our energy usage immediately. In Sweden, the government has the goal of decreasing energy usage with about 20 % from 1995 to 2020, and 50% by 2050. Almost 40% of all energy usage is from the construction and property sector. However, to decrease energy usage within that sector we have to make current buildings more energy efficient. A major part of energy usage in the constructions sector goes to cover transmission losses through walls, windows, and thermal bridges. So, by choosing windows with low heat transfer and the correct isolation for the specific buildings, as well as, decreasing transmission losses through ventilation and heating would result in that a lot of energy can be saved. If a building has a low transmissions lose, the demand of energy would decrease remarkably. By installing ventilations systems with the function of heat recovery (FTX) so could the energy usage regarding preheated ventilation decrease heavily. While, the ventilation and heat recovery makes it possible to reuse energy from the outgoing air from the facilities to the cold air outside that shall be used in the facilities to maintain a good indoor environment; heat exchangers have an efficiency level of 0.85. To make old buildings energy efficient, it requires new installations and remodeling to adjust them to become environment friendly buildings. It can sometimes be hard to install FTX-systems in current buildings since air-handling units requires a lot of space, and that the financial write-off periods can be long. This thesis will investigate the ventilations- and preheating systems with a focus in installation technics and energy efficiency depending on how the facility will be used. The goals are to investigate how large the demand for energy is in a building, as well as, give suggestions to which ventilations systems that would fit best with the prospective building. With drawings of a locomotive workshop and miscellaneous information about the facility, and a model of the facility by the simulation program IDA ICE the energy demand in the building was simulated. When a model had been created the work with inputs and changes were made on the buildings - with help from input that has been receive from the client. Drawings of the ventilation were performed in Magi Cad and an air handling has been dimensioned on Swegon’s website. The temperature in the facility is affected by several factors, such as poor isolation etc. The facilities are not heated today besides through local heating at extreme low temperature to maintain a sufficient heat to not freeze the HVAC. The facilities have high moisture level, and at the same time some parts of the floor are made of very thick concrete plates. The results of the tests show that the best ventilation unit that is needed to manage the air flow of 11.6 (m3/s) should have the specific fan power of 2. 39 kW/ (m3/s). The buildings energy use became 610624 kWh/year in the simulation. / <p>Vi redovisade i september 2015 men blev hel godkänd nyligen. Jag visst inte om jag vilket år som gäller(2015 eller 2016)</p>
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Värmeförluster vid utvändigt placerade ventilationssystem / Thermal heat losses on exterior ventilation systemsAhlgren, Tobias, Eliassi, Jalal January 2012 (has links)
To be able to handle tomorrows need for limited energy consumption we need to reduce our use of energy. The building sector stands for around 40 % of all energy consumption in the society. The government has put up a goal to reduce the energy consumption in our buildings with 20 % by year 2020 and 50 % by year 2050 compared with year 1995. To be able to do reach that goal we need a more energy efficient building stock. The main part of the energy used in our buildings is used for space heating. By installing ventilation systems with heat recovery on the exhaust air it is possible to use the heat-energy in the exhaust air to warm up the incoming air. This can contribute to a reduction in energy use. A ventilation system with heat recovery on the exhaust air is space demanding and there can be problems with finding enough space to do the installation indoors. Therefore it can be an advantage to place the aggregate and the ducts on the outside of the buildings climate shell. A placement exterior of the buildings climate shell or in an unheated space leads to thermal heat losses. The aim with this essay is to investigate how significant the heat losses are on exterior placed ventilation systems. The investigation has been done with help of theoretical calculations and measurements of the temperature difference in the ventilation ducts. Analysis has been made on life cycle costs on how to reduce the heat losses in an economic manner. To buildings, Höstvägen 14 and 22 in Växjö, which have been equipped with exterior placed ventilation systems have been studied. The two buildings have two different types of installation of the ducts. Our result shows that the heat losses through the ventilation systems on Höstvägen 14 and 22 are significant. The majority of the losses occur in the ducts. In the aggregate the thermal bridges in the framework accounts for the larger part.
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Mateřská škola v Třebíči / Nursery school, TřebíčSvoboda, David January 2016 (has links)
This diploma thesis on a topic “Nursery school in Třebíč” deals with a new building proposal of a nursery school. The building is situated in Třebíč, in a densely populated part of the town which is called Podklášteří. It is a brick single-storey detached building, mounted on a gentle slope with green vegetation. The layout of the building is divided into three departments and an operational part. In each department, there is a dressing room, food distribution, study and dining room, playroom with a cushy job, toy store, warehouse of folding beds and bedding, washroom, toilet, utility room and room for the air handling units. Departments are covered by wooden trusses which bear single-layer saddle-shaped roof with an extensive green vegetation. Above the operational part, there is a single-layer flat roof. Wall system is made of ceramic blocs of a system Porotherm and trusses are from a company called Vazníky D.N.K.
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